On Tue, May 09, 2023 at 08:29:50AM +0200, Corentin Labbe wrote:

The bios speak about a debug port, but I found nothing which seems a
physical debug port output.  I tried to wire the microusb power port
on a USB host, but the host fail to enumerate any device (I tried also
a spetial USB cable with data/power separated to be sure the problem
was not the host failling to give enough power)

The tablet has only one port, so I use a hub for keyboard and USB key.

USB debug port is probably that one port, USB debug also does not work
through a hub :/

USB debug in general is a giant pain in the rear and I've never had much
luck with is. If it's that old to still need a i386 kernel then it's
probably USB2 at best and that requires a special magical cable too :-(